Beolab 3500 Mk II
Tested with SW 3.33
When the Beolab 3500 Mk II is in PL mode, it behaves like a normal BL speaker (BL6000, BL8000): no IR reception, no SelectSource, and also no Vol+/Vol-. A speaker like that having its own display doesn’t really make sense in the first place.
⚠️ Big warning: PL-level audio signals are much lower than a typical Line In / audio jack level. Since the Beolab 3500 Mk II’s volume can’t be controlled over PL (see above), feeding it a normal Line-In-level signal directly risks destroying it. Attenuate the input first — a voltage divider, or a level control on the source device — before connecting it.
The basic idea
Without display
Simple, two things needed — tie PL4 to +5V, and send 0011000111100111111100000000100 on PL6 / PL7.
With display
It gets more complicated — two additional requirements:
Mute BL Pin4 must only go HIGH after that init sequence (0011000111100111111100000000100) has finished sending — it has to stay LOW for the whole duration of the sequence.
⚠️Remark : Sending PL commands to BL3500 its different than usual PL commands:
After the frame’s normal Stop (t4), one more t1 pulse (3.125ms) is required!During dev Beolab3500MKII_PL i recognize that the additional t1 in only needed for the init sequence. All other PL commands are as usual